1. Field of the Invention
The invention relates to a burner for pulsating combustion with an explosion chamber which on the inlet side connects to a supply tube for combustion air and a supply tube for fuel and on the outlet side is connected to one or more discharge tubes for the combustion gases, as described in the Netherlands patent application NL-A-89 01416 of applicant.
2. Description of the Prior Art
In such a burner as described in Netherlands patent application NL-A-89 01416, the explosion chamber and the supply and discharge tubes serving as resonance tubes are dimensioned such that the frequency of the periodic ignitions of the combustible mixture in the explosion chamber corresponds with the natural frequency of the gas mass in these tubes and the explosion chamber.
Due to the inertia of the gases flowing in the discharge tube there results an underpressure in the explosion chamber after combustion, whereby on the one side fuel and air are drawn in and on the other side hot combustion gases flow back to the explosion chamber which ignite the combustible mixture that has flowed in. A cyclic process hereby results which pulsates with a frequency substantially dependent on the dimensions of the explosion chamber, the supply and discharge tubes and the nature of the fuel.
Such devices are employed for heating, drying, concentration by evaporation, driving gas turbines, etc. and have the advantage of a high heat transfer coefficient, whereby the device can take a compact form while a practically complete combustion is obtained at an air factor 1 with almost no emission of CO and very little formation of NO.sub.x.
In non-damped embodiments the explosion of the fuel produces a great deal of noise (between 90 and 140 db(A)), which produces a nuisance for the surrounding area.